Cryo-balloon Angioplasty of Pulmonary Vein Stenosis: Successful Therapy or “Freezer Burn”

  • Dr Michael Bingler, The Children's Hospital Denver, United States
  • Dr Jeffrey Darst, Children's Hospital Boston, United States
  • Dr David Balzer, St. Louis Children's Hospital, United States
  • Dr Thomas Fagan, The Children's Hospital Denver, United States

    • Objective: Current therapy for most forms of pulmonary vein stenosis (PVS) is less than satisfactory due to recurrent, progressive re-stenosis and neointimal proliferation. We sought to determine the safety and effectiveness of cryo-balloon angioplasty (CbA) for PVS in pediatric patients.

    Methods: We reviewed the catheterization database, hospital records, imaging studies and pathologic specimens in all patients who had pulmonary vein (PV) CbA using Boston Scientific PolarCath ™ peripheral dilation system.

    Results: Ten patients (13 PVs) had CbA from 8/06-12/08. Median age 18 months (4 mo-18.5 yrs), weight 8.9kg (3.8-47.7). Five had additional structural heart lesions (2 repaired TAPVR). Three PVs had previous surgical and 4 previous transcatheter therapy. Median balloon size/stenosis diameter and balloon size/normal vessel diameter ratios were 2.69 (1.82-3.33) and 1.2 (0.87-2.07). Results are summarized below. Six patients (11 PVs) had follow up cath 6 months (± 4.1) later. Improved PVS diameter was maintained in only 2 PVs. Two veins had restenosis but maintained diameter greater than before initial CbA. All vessels had repeat intervention with acute relief of PVS. Stroke occurred within 24 hours of CbA in one patient. One patient underwent lung transplantation after repeat non-CbA and PV stent. Two patients died; one of progressive PVS 2.5 months after initial CbA and one of unknown cause 3 months after second CbA.

    Conclusion: Cryo-balloon angioplasty of pulmonary vein stenosis is safe and results in acute relief of stenosis. However, cryo-balloon angioplasty appears minimally effective as sole therapy in maintaining long term relief of pulmonary vein stenosis.

    Stenosis Diameter (mm) Mean Gradient (mmHg) Stenosis: Normal Vessel Ratio Stenosis Diameter at Follow Up (mm) Mean Gradient at Follow Up (mmHg)
    n 13 13 13 11 11
    Pre 2.4 (± 0.6) 12.3 (± 6.9) 0.55 (± 1.9)
    Post 4.1 (± 1.1) 3.6 (± 2.9) 0.98 (± 3.6) 5.0 (± 2.1) 2.55 (± 2.2)
    F/U 2.67 (± 1.2) 13.1 (± 10.0)
    p value <0.001 0.001 <0.001 0.003 0.017